TEHRAN — The brother of Iran’s president walked into Tehran’s only Jewish hospital on Thursday, delivering a surprise donation along with the message that the Health Ministry would give more attention to hospitals that traditionally serve Christian and Jewish Iranians.

“We are very happy,” a nurse there said by telephone. “This is a good sign.”

The hospital, the Dr. Sapir Hospital and Charity Center, received $400,000 from the government of President Hassan Rouhani, the semiofficial Mehr News Agency reported. Another Iranian source, the semiofficial website Tabnak, said that the amount was $200,000, but that a second installment in the same amount would be coming.

The leader’s brother, Hossein Fereydoon, who goes by Mr. Rouhani’s original family name, was quoted by Tabnak as saying, “Our government intends to unite all ethnic groups and religions, so we decided to assist you.”

Since taking office in August, Mr. Rouhani has embarked on a campaign to engage the world after years of isolation under his predecessor, Mahmoud Ahmadinejad, who never missed an opportunity to denigrate Israel and deny that six million Jews had died in the Holocaust.

Mr. Rouhani’s approach toward Jews and the care he takes when mentioning Israel form a central part of his effort to undo some of the damage — international censures and sanctions — from Mr. Ahmadinejad’s two terms.

The gift to the hospital comes after the president’s social media team wished Jews around the world a happy Rosh Hashana, in September. In stark contrast to Mr. Ahmadinejad, Mr. Rouhani rarely mentions Israel and avoids talking about the Holocaust.

While the Islamic republic’s ideology prescribes that Israel — “the Zionist regime,” as it is referred to here — is a mortal enemy, never to be recognized, Iran is also home to the largest population of Jews in the Middle East after Israel, though that number is dwindling. Jews are an officially recognized minority, with a population of about 9,000.

“We can clearly see that Mr. Rouhani is trying to take distance from Mr. Ahmadinejad’s Holocaust-denial policies,” said Farshad Ghorbanpour, a political analyst close to the government.

Some are interpreting Mr. Rouhani’s gentler approach toward Israel as a policy change, pointing to several Middle Eastern meetings to which both countries sent representatives, even though Iran does not officially recognize Israel.

During the Munich Security Conference last Saturday, the Iranian foreign minister, Mohammad Javad Zarif, gave an interview in which he was reported to have said that Iran could consider recognizing Israel someday.

“After the problem with the Palestinians is resolved, the conditions that will enable recognition of the State of Israel will be established,” he was quoted as telling a German television station, Phoenix.

In a separate speech at the conference, Mr. Zarif said the Holocaust was “tragically cruel and should not happen again.”

On Thursday, Mr. Zarif denied the comments attributed to him during the interview, saying his words were distorted. He did not deny his comments about the Holocaust.

Meir Javedanfar, an Iranian-Israeli who teaches Iranian politics at the Interdisciplinary Center in Herzliya, Israel, said Mr. Rouhani’s gestures were “rare for recent years,” and described Mr. Zarif’s remarks about an Iranian decision regarding relations with Israel in the event it finalizes a peace deal with the Palestinians as “a first in itself.”

“They may or may not decide to recognize Israel,” Mr. Javedanfar said in a telephone interview, “but to say that they will decide on it is unprecedented.”